Hand-held orbital sanders and other handheld abrading or abrasive tools are common in the prior art having been available to the general public for several decades. One problem common to handheld (portable) powered sanders, including orbital sanders, is the tool grip is configured in such a way that the user is required to arch his wrist, which over a period of time will tend to cause wrist strain and eventually chronic injuries such as carpal tunnel syndrome. Typically, the user must grip the sander on top of the housing with the abrasive material, such as a sandpaper sheet, attached to the rotating bottom of the sander. In order to provide sufficient pressure to the abrasive tool, the user must press down on the top of the housing while at the same time arching the wrist out of the way of the attached air hose, for pneumatic sanders, power cord, and/or dust and air exhaust. This problem may be exacerbated by the addition of a dust collection bag attached to the exhaust. In several embodiments, the hand must simultaneously hold down a “dead-man” type power switch. These strained gripping positions can lead to long-term, if not permanent damage to the hand, wrist, and/or distal portion of the forearm. Although there exist innumerable embodiments of handheld sanders, they fail to disclose a sander with an ergonomically comfortable gripping surface for handheld sanders, including rotary sanders.
U.S. Pat. No. D494,434 to Sun, et al. is typical in that it discloses a handheld pneumatic burnishing device having a relatively large switch that is held by the gripping hand as the burnishing device is operated. An air inlet and exhaust extends out from the housing under the switch. Because the '434 device lacks a hand or wrist support or rest, the user is required to arch his/her wrist and cup the hand in order to hold the switch and simultaneously maneuver the tool on the surface to be treated.
U.S. Pat. No. D458,102 to Tseng and U.S. Pat. No. D438,078 to Leu are similar in structure to the tool in the '434 patent in that they include a switch held by the gripping hand and they also lack any type of wrist or forearm resting device or a guard to prevent the wrist or forearm from contacting either the inlet or inlet hose and the exhaust duct or bag. U.S. Pat. No. D436,817, also to Leu, features a dust bag outlet that extends from underneath the switch, but provides no stable component on which to rest the gripping hand's wrist or forearm. U.S. Pat. No. D353,984 to Izumisawa discloses an orbital sander similar to that of the '817 patent in that the exhaust duct extends some distance from the housing of the sander. However, the exhaust duct, aside from possessing a curved shape unsuitable for supporting a wrist, is also positioned below the level of the switch, making it unavailable for a wrist or forearm rest even if the shape of the duct was more suitable.
U.S. Patent Publication No. 2003/0228833 to Boyer is typical of handheld sanders and other similar abrasive tools designed to be held with two hands in that the switch is located under one of the handles and it can only be effectively operated using two hands. In addition, it lacks any component that can be used as a guard or rest for supporting the wrist or forearm.
Therefore, there is a need in the field for an orbital abrasive tool ergonomically designed to be held with one hand and that provides a guard or rest for the user's wrist or forearm to prevent carpel tunnel syndrome and other injuries to the gripping hand.